Spotted at "15-Jahre-Geocaching"-Event in Essen. The event was held at Zeche Zollverein.
Here is some information you may find interesting: 100 hectares in the north of Essen, Shaft XII, Shaft 1/2/8 and coking plant Zollverein. The first shaft was sunk in 1847, the last coal mined in 1986 and the coking plant shut down in 1993. The buildings and facilities have been officially listed as historic monuments since 2000, which was followed in 2001 by their acceptance into the ranks of UNESCO World Heritage Sites. The motto is preservation through alternative use.
Have a nice journey.
Greetings from Duisburg/Germany to the US,
RatpackDU